What makes a planet a planet? Why haven't we gone back to the moon? What'll happen to the International space station when we're done with it? Dr Karl is away for the month, so science journalist Bianca Nogrady is stepping in to be your science sherpa on triple j. Joining her today was Professor Lisa Harvey-Smith, astrophysicist with the CSIRO!

Dr Karl is away for the month, so science journalist Bianca Nogrady is stepping in to be your science sherpa on triple j. And joining her today was Dr Alice Williamson, chemist from the University of Sydney.

Dr Karl is away for the month, so science journalist Bianca Nogrady is stepping in to be your science sherpa on triple j. And joining her today was Professor Clare Collins, Nutritionist at the University of Newcastle.

Dr Karl is away for the month, so science journalist Bianca Nogrady is stepping in to be your science sherpa on triple j. And joining her today was Professor Clare Collins, Nutritionist at the University of Newcastle.

Dr Karl is away for the month, so science journalist Bianca Nogrady is stepping in to be your science sherpa on triple j. And joining her today was Dr Jess Bloom, astrophysicist from the University of Sydney.

Dr Karl is away for the month, so science journalist Bianca Nogrady is stepping in to be your science sherpa on triple j. And joining her today was Dr Jess Bloom, astrophysicist from the University of Sydney.

Why do you always see dead cockroaches on their backs? Why is bellybutton fluff always dark blue? And could you get drunk from breast milk if the mother has been drinking?

Why do you always see dead cockroaches on their backs? Why is bellybutton fluff always dark blue? And could you get drunk from breast milk if the mother has been drinking?

What's 'visual snow'? Why will a dripping tap wake you up but torrential rain won't? Why do some people wake up grumpy?

What's 'visual snow'? Why will a dripping tap wake you up but torrential rain won't? Why do some people wake up grumpy?